"Specialization is for insects. A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly." -- Heinlein
Also "I'm an engineer". People with specific vocational training (EE, MD, whatever) think because they know one thing well enough to get a professional license they know all things well.
I'm seeing a pattern here...